1 // SPDX-License-Identifier: GPL-2.0-or-later
5  *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
6  *  Copyright 2003-2004 Jeff Garzik
15  * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
18  * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
19  * These were taken from ATA/ATAPI-6 standard, rev 0a, except
57 #define ENOUGH(v, unit)		(((v)-1)/(unit)+1)
63 	q->setup	= EZ(t->setup,       T);  in ata_timing_quantize()
64 	q->act8b	= EZ(t->act8b,       T);  in ata_timing_quantize()
65 	q->rec8b	= EZ(t->rec8b,       T);  in ata_timing_quantize()
66 	q->cyc8b	= EZ(t->cyc8b,       T);  in ata_timing_quantize()
67 	q->active	= EZ(t->active,      T);  in ata_timing_quantize()
68 	q->recover	= EZ(t->recover,     T);  in ata_timing_quantize()
69 	q->dmack_hold	= EZ(t->dmack_hold,  T);  in ata_timing_quantize()
70 	q->cycle	= EZ(t->cycle,       T);  in ata_timing_quantize()
71 	q->udma		= EZ(t->udma,       UT);  in ata_timing_quantize()
78 		m->setup = max(a->setup, b->setup);  in ata_timing_merge()
80 		m->act8b = max(a->act8b, b->act8b);  in ata_timing_merge()
82 		m->rec8b = max(a->rec8b, b->rec8b);  in ata_timing_merge()
84 		m->cyc8b = max(a->cyc8b, b->cyc8b);  in ata_timing_merge()
86 		m->active = max(a->active, b->active);  in ata_timing_merge()
88 		m->recover = max(a->recover, b->recover);  in ata_timing_merge()
90 		m->dmack_hold = max(a->dmack_hold, b->dmack_hold);  in ata_timing_merge()
92 		m->cycle = max(a->cycle, b->cycle);  in ata_timing_merge()
94 		m->udma = max(a->udma, b->udma);  in ata_timing_merge()
102 	while (xfer_mode > t->mode)  in ata_timing_find_mode()
105 	if (xfer_mode == t->mode)  in ata_timing_find_mode()
118 	const u16 *id = adev->id;  in ata_timing_compute()
120 	struct ata_timing p;  in ata_timing_compute()  local
127 		return -EINVAL;  in ata_timing_compute()
137 		memset(&p, 0, sizeof(p));  in ata_timing_compute()
141 				p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO];  in ata_timing_compute()
144 				p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO_IORDY];  in ata_timing_compute()
146 			p.cycle = id[ATA_ID_EIDE_DMA_MIN];  in ata_timing_compute()
148 		ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);  in ata_timing_compute()
158 	 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY,  in ata_timing_compute()
164 		ata_timing_compute(adev, adev->pio_mode, &p, T, UT);  in ata_timing_compute()
165 		ata_timing_merge(&p, t, t, ATA_TIMING_ALL);  in ata_timing_compute()
172 	if (t->act8b + t->rec8b < t->cyc8b) {  in ata_timing_compute()
173 		t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;  in ata_timing_compute()
174 		t->rec8b = t->cyc8b - t->act8b;  in ata_timing_compute()
177 	if (t->active + t->recover < t->cycle) {  in ata_timing_compute()
178 		t->active += (t->cycle - (t->active + t->recover)) / 2;  in ata_timing_compute()
179 		t->recover = t->cycle - t->active;  in ata_timing_compute()
184 	 * leave t->cycle too low for the sum of active and recovery  in ata_timing_compute()
187 	if (t->active + t->recover > t->cycle)  in ata_timing_compute()
188 		t->cycle = t->active + t->recover;  in ata_timing_compute()